Improvement in printing-telegraphs



3 Sheets-Sheet l. T. A. EDISON. Printing Te'legraphs.

Patented )uU/1,1873.

3SheetsSheet2. T. A. EDISUNu Printing Telegraphs.

510.140,488. Patenledjuly,l873.

vayan 3 Sheets-Sheet 3.

T. A. EDISON. Printing Telegraphs.

Patented July 1, 1873.

THOMAS A. EDISON, OF NEWARK, N AND STOCK TELEGRAPH CO EW JERSEY, ASSIGNOR TO THE GOLD MPANY, OF NEW YORK, N. Y.

IMPROVEMENT IN PRINTING-TELEGRAPHS.

Speciication forming part of Letters Patent No. 140,488, dated July l, 1873 g application filed May 1o, 1873.

To all whom it may concern:

Be it known that I, 'THOMAS A. EDrsoN, of Newark, in the county of Essex and State of New Jersey, have invented an Improvement in Printing-Telegraphs, of which the following is a specification In this machine there is a circuit-breaker driven by an electric engine, and this pulsa-tor makes and breaks the circuit ofthe main line and causes all the type-wheels in the circuit to revolve in unison through the agency of an electro-magnet and step-by-step mechanism. When a key at the transmitting-station is de pressed it stops the circuit-breaker and arrests the movement of the type-wheels. At each station is a local battery that is brought into action by the cessation in the movement of the type-wheel lever closing the circuit and throwing the current into the printing-magnet.

In the drawing, Figure 1 is an inverted plan, representing the principal portions ofthe meehanism. Fig. 2 is a vertical section, showing the operative portions of the machine; and Fig.3 is a general plan view on a smaller scale, representing the connections.

The hed a ofthe machine is of' suitable size and shape, and around on one side is a range of ngerkeys, b, occupying onethird of the circle, and these are connected with the bars b', beneath the bed a, that stand radially around the wheel h4 that is in the middle of the bed, and is hereafter referred to. The type-wheel c is revolved by a step-by-step movement from the lever d, electromagnet di, and spring 3. The unison mechanism c and the printing-lever e1 and magnet c2 are similar to those in my patent N o. 126,532. The feeding mechanism for the paper is similar to that in my patent No. 126,532, and there is a pawl and retaining-clamp, 4, to prevent the paper drawing back, asin said patent. The motor consists of the electro-magnets f f vertical shaft g, and governor-balls g1, and the speed is regulated by short-circuiting the battery-connection by the collar 5 and linger 6, as in my patent No. 131,343. The connections are made as shown in Fig. 3 5 the binding-screws 7 and 8 are the line-connections, or line and earth. The connection 9 is to the engine, and 10 to the printing-magnet, and 1l is the return-connection to the local battery g2. The motor drives the wheel 71. by the pinion 13, and this communicates motion to the pinion 14 and a wheel, h, to which is attached a ratchet-wheel, It. The wheel h4 is loose upon the same shaft as the wheels h1 and k, and it is rotated by a pawl, 15, that is upon'the wheel h4, and takes the teeth of the ratchet-wheel lc. The arms m, three in number, project from a hub around the shaft h3. One of them is contiguous to a knuckle on the pawl 15, so that when one ot' the finger-keys I1 is depressed, and one of the arms m comes into contact with the bar b ot' the depressed key, then the arms m are arrested, and the wheel h4, moving slightly by the pawl, brings the knuckle of the pawl into contact with said arm in, andV throws the pawl out from the ratchet-wheel k, thereby allowing the ratchet-wheel lc and wheel h1 to contin ne to revolve, but stopping the wheel h4 and the parts deriving motion from it. Y In this manner the circuit-closing wheel o is stopped, said wheel receiving motion from the pinion o2, and.

as soon as the finger-key is raised the spring o3 throws the pawl 15 back into contact with the ratchet-wheel la, and the motion ot' the circnit-closing wheel is renewed. The lever s is operated by camfprojections on the wheel o, and, by the contact-points 20 and 35, and springs 2l, the circuit next described is opened and closed. There is an insulated block, t, upon which the springs 22, 23, 24, and 25 rest, and in it are conducting-blocks. When a knob above the bed ofthe machine is turned to the word take]7 the circuit is closed through'the springs 22 and 23. When it is turned to the word send,77 the circuit is closed through 2L and 25. The parts are so timed that the number of times the circuit is opened and closed during each revolution of the Wheel l1.4 equals three times the number of the keys b, and hence that the pulsations acting in the line make three revolutions of the typewheel, the pulsations passing by the binder 7, wire 37, screw 36, metallic frame and lever s, contactpoints 20 35, springs 21, and connection to the binder 33, wire 32, magnet d1, wire 3l, and binder 8, and thence along the line to the distantinstruments,and settingtheirtype-wheels,

is 140,488' I and when the revolution of h4 is stopped by depressing a key, the letter of the type-wheels corresponding to that on the depressed key is in position for printing. At the receiving instrument the block t is turned to take, and the circuit-closer is no longer included in the circuit, but the pulsations go direct through the magnet d1 to set the typewheel, the route being by binder 7, wire 37, binder 36, wire 38, spring-arms 22 and 23, wire 39, binder 33, wire 32, magnet d1, wire 3l, and binder S to line or earth connection. While the type-wheel lever d is vibrating the spring d3 thereon does not remain iu contact long enough with the anvil d* to energize the printing-magnetcz; but so soon as the pulsation in the type-wheel magnet ceases the circuit is closed through d3 and d4, the current passing by binder 10, wire 40, magnet e2, wire 49, anvil d4, spring d, lever el, frame and bed a, and binder 11 back to battery g2, and the printing effected. The fulcrum of the printing-lever cl is to be loose in its bearings, so that the momentum may carry the lever and its pad up to the type and produce the impression, and then fall away to prevent blurring the letter when the type-wheel s again revolved. The brass screws e6 passing through the armature of the lever el, coming into contact with the cores of e2, prevent adhesion between the surfaces and adjust the blow of the impression-pad. A ratchet-wheel, m5, upon the governor-shaft g is provided, and a springpusher, 'm6, is used to start the governor and motor in the right direction when the machine is put into motion. The contact-points 20 and spring contact-points 35 are in pairs, as seen in the detached view, Fig. 4, and two of the points touch before the other two, the object being to lessen the risk of false or defective pulsations, because the intensity of the spark between the contact-points produces oxidation that sometimes prevents the transmission of the pulsation. This spark is between thepoiuts that first come into contact; but if the spark fails between these it passes between the second Vpair of contactpoints, and. because this second pair is so seldom exposed to the action of the spark, their surfaces remain free from oxidation a very long time.

Stop-pawls have been `used to prevent the type-wheel turning back, but they have been employedin connection with spring-pawls or on a separate ratchet-wheel. I employ the pawl e7 and spring el? in connection with the wedge-acting pallets shown, and such pawl is soconstructed that it prevents the type-Wheel being turned the wrong way by holding the type-wheel in place when the pawls are not in contact with the ratchet-wheel, but are moving from one side to the other.

I claim as imy invention- 1. The circuit-breaking wheel o actuated by the wheel h4, in combination with the pawl 15, ratchet-wheel lc, arms m, and range of fingerkey bars b', substantially as and for the purposes set forth.

2. The switch-block t, circuit-springs 22 23 24 25 and their connections, substantially as set forth, in combination with the circuit-closer o, line-connections and type-wheel magnets d1, substantially as set forth.

3. The starting mechanism, consisting of the pawl m6 andratohet-whee-l m5, in combination with the governor and magnetic motor, snb stantially as set forth.

4. The screws e6 applied to the armature of the printing-magnet, for the purposes set forth.

5. The stop-pawl e7, in combination with the type-wheel, wedge-acting pallets, and ratchetwheel, for the purposes set forth.

6. The double pairs of spring circnit-closing points 2O and 35, one pair set to come into contact before the other pair, for the purposes set forth.

Signed by me this 23d dayof April, A. D.

THOS. A. EDISON. Witnesses:

Unas. H. SMITH, Gno. T. PnvcKNEY. 

